| I don't believe the glucose/insulin relationship is strictly linear. As body glucose increases there will often be a disproportionate increase in insulin requirements. Agreed, this shouldn't really happen with a balanced calorific intake. Moderation in CHO intake should lessen the chance of even slight insulin resistance.
I don't think we need to make any distinction between T1 T2 and ND here. Insulin resistance CAN occur in any group.
I've only been reducing my CHO intake over the last two months or so, and have not really yet settled into a rhythm in terms of diet. My average reading is about 90 (5 mmol) and I prefer not to let it exceed 6 mmol (108) where possible. I think as time goes by you get to recognise more patterns and are able to fine tune your diet and insulin.
Provided your basal dose is not being used to lower BS you shouldn't risk night time hypos. Ideally a basal insulin should suffice for basal metabolic requirements and no more. Any need to reduce high sugars or to cover meals and snacks is more easily covered with smaller quantities of faster acting insulins.  | 
